Echinocereus papillosus

Plants irregularly forming clumps at or before flowering. Stems mostly nearly erect when young, frequently decumbent in old age, cylindric, 4-15 × 2-3(-7) cm; ribs (6-)7-10, crests strongly undulate; areoles 10-15 mm apart. Spines 8-12 per areole, straight, appressed-spreading (radial spines) or projecting to appressed (central spines), white, yellow, or brown and white; radial spines 7-10 per areole, to 15 mm; central spines 1(-4) per areole, brown, terete, to 25 mm. Flowers funnelform, 7-9 × 7-12 cm; flower tube 20-30 × 10-30 mm; flower tube hairs 1 mm; inner tepals yellow, proximally orange-red to purple, 15-40 × 10-20 mm, tips relatively thin and delicate; filaments yellowish to orange-red; anthers yellow; nectar chamber 4-6 mm. Fruits green, 15-25 mm, pulp white. 2n = 22.

Flowering early spring; fruiting 2 months after flowering. Open prairies with mesquite, Tamaulipan thorn scrub, alluvium, red gravel, limestone; to 150 m; Tex.; Mexico (Nuevo León, Tamaulipas).

Small-stemmed plants were designated as Echinocereus papillosus var. angusticeps (Clover) W. T. Marshall, reportedly endemic near Linn, Texas. The status of the proposed variety remains unresolved but appears weak; W. Blum et al. (1998) and E. F. Anderson (2001) considered the name to be a synonym of typical E. papillosus.